Pump



March 9, 1965 w. H. MASHINTER PUMP 3 Sheets-Sheet 1 Original Filed July24, 1958 WWW wmm

BY film m),

PUMP

3 Sheets-Sheet 2 Original Filed July 24, 1958 w W W 0 7 .U y @mW March9, 196 w. H. MASHINTER 3,172,363

PUMP

Original Filed July 24, 1958 3 Sheets-Sheet 3 t 45 INVENTQR.

States are The present invention relates to a novel fluid pumpingstructure. This is a division of my copending application Serial No.750,760 filed July 24, 1958, now Patent No. 3,070,030.

The present invention relates particularly to positive displacementpumps suitable for a wide variety of uses as well as for installation inthe specific pumping structure disclosed in the aforementioned copendingapplication. It is an important general object of the present inventionto provide a novel pump capable of relatively accurately and eflicientlyproviding a variable output while at the same time being constructed ina manner which promotes more economical production.

An object of the present invention is to provide a novel fluid pumpincluding reciprocable piston means actuated by rotary cam or Wobbleplate means on a rotary shaft, which pump is constructed so as toeliminate any need for heavy thrust bearings for the shaft.

Another object of the present invention is to provide a novel fluid pumpor driver including reciprocable piston type pumping means, which pumpis constructed so as to start pumping action when the piston means hasZero velocity whereby to obtain a substantially shockless pumpingstation.

Further object of the present invention is to provide a novel fluid pumpor driver of the above described type which is constructed so as toprovide a substantially constant fluid flow or output.

Still another object of the present invention is to provide a novelfluid pump utilizing reciprocable piston pumping means, which pump isadjustable so that the output thereof may be varied in infiniteincrements and so that complete filling of pumping chamber means duringeach stroke of the piston means is obtained regardless of any adjustmentfor controlling the output whereby a substantially constant compressionratio and more uniform and etlicient pumping action are obtained.

A more specific object of the present invention is to provide a novelfluid pump which is constructed so that when it is adjusted for reducingthe fluid output, a portion of the fluid will be circulated within thepump so as to reduce agitation of the fluid and power losses.

Still another object of the present invention is to provide a novel pumpincluding a plurality of reciprocable piston means, which pump isconstructed so that a single element controls the output of all of thepiston means whereby construction is simplified and made more economicaland close manufacturing tolerances are not required since any error inthe control element will be introduced into the output of all of thepiston means.

Qther objects and advantages of the present invention will becomeapparent from the following description and the accompanying drawingswherein:

FIG. 1 is a sideelevational view showing a pumping structure including apump or driver incorporating features of the present invention;

FIG. 2 is a front elevational view partially broken away for showingcertain features of the pumping structure;

FIG. 3 is an enlarged sectional view showing fluid pump or driver meansconstructed in accordance with features of the present invention andadapted to be installed in the pumping structure shown in FIGS. 1 and 2;

FIG. 4 is an enlarged fragmentary sectional view taken generally alongline 4-4 in FIG. 1;

3,172,358 Patented Mar. 9, 1965 FIG. 5 is a cross sectional view on areduced scale taken generally along line 5-5 in FIG. 3;

FIG. 6 is a fragmentary partial sectional view taken generally alongline 6-6 in FIG. 3;

FIG. 7 is a fragmentary cross sectional view taken along line 7-7 inFIG. 6; and

FIG. 8 is a perspective view showing a control element of the fluid pumpor driver structure constructed in accordance with features of thepresent invention.

Referring now more specifically to the drawings, wherein like parts aredesignated by the same numerals throughout the various figures, apumping apparatus 30 including a pump 36 incorporating features of thepresent invention is shown generally in FIGS. 1 and 2.

The apparatus 30 is one installation in which the pump 36 is ofparticular value, but it is to be understood that the pump 36 issuitable for various uses. For a complete disclosure of the apparatus 30reference is made to the above mentioned copending application. Itsuflices to state here that the apparatus 30 comprises an upstandingframe 32 which provides a sump or reservoir 34 for actuating fluid orhydraulic oil which is to be pumped in the manner described below. Inorder to provide suflicient power for enabling the pumping apparatus todeliver relatively high volumes of fluid without unduly increasing thesize and weight of the apparatus, the high speed fluid pump or drivermeans 36 is mounted within the reservoir 34. A high speed electric motor33 or other suitable prime mover is mounted on the frame 32 foractuating the pump 36. As indicated in FIGS. 1 and 3, an output shaft4-6 of the motor is connected with a rotatable shaft 42 of the driver bysuitable coupling means 44. It will be understood that in other types ofinstallations, different means may be provided for driving the pumpshaft 42.

The pump 36 is adapted to deliver a continuous and substantiallyconstant stream of fluid or oil under pressure. This stream of fluid isdirected by conduits 46 and 43 to a diaphragm pump assembly 50 which issecured to a side of the frame means 32. As is described in theaforementioned copending application, the pump assembly 50 is adapted tobe actuated by the fluid under pressure from the pump36.

Referring particularly to FIGS. 1 and 3 through 8, the pump 36 will nowbe described in detail. The pump is provided with a main body member 52having a central aperture 54 through which the rotatable shaft 42extends. Cylindrical members 56 and 58 are respectively disposed againstends of the body member 52 and provide annular chambers 66 and 62 whichare traversed by opposite end plates 64 and 66. The end plate 64 and thecylindrical member 56 are secured to the body member 52 by a pluralityof screws 68. The end plate 66 and the cylindrical member 58 aresimilarly secured to the body member by a plurality of screws 70.Bearing assemblies 72 and 74 are mounted in suitable recesses providedin the end plates 64 and 66 respectively for rotatably supporting theshaft 42. It is to be noted that the structure does not include anyheavy or substantial thrust bearing means for preventing axial shiftingof the shaft 42 whereby the structure is simplified and made moreeconomical. This feature is one result of other features described indetail below.

As shown in FIGS. 3 and 5, the body member 52 is provided with aplurality of piston accommodating bores or pump chambers 76 equallyspaced about the axis of the body. Preferably there is an odd number andat least three of these bores and associated piston pumping means sincesuch an arrangement facilitates phasing of the pumping action of thepiston means associated with each bore so that the driver is capable ofdelivering a substantially continuous and constant stream of fluid.Opposed pis- 3 tons 78 and 80 are reciprocably mounted in opposite endportions of each of the bores 76. Inlet openings or passageways 82 areprovided in the body member 52 for each of the bores 76, whichpassageways are located midway between the opposite ends of the bores'76 and communicate with the central bore or chamber 54 of the bodymember. Preferably the driver 36 is adapted to be mounted substantiallycompletely submerged in the body of oil in the reservoir 34. Thus, oilfrom the reservoir will flow into the driver and completely fill thechambers 6t), 62 and 54 so that a supply of oil is available forentering the inlet ports 82. The opposite end assemblies of the driverare not fluid-tight so that oil may readily enter the driver chambers 60and 62, and if desired openings, not shown, may be provided through theend plates 64 and 66 to facilitate entry of the oil into the driver. Thebody member 52 is provided with a plurality of outlet passageways 84which extend radially from the bores 76 and are located so as tocommunicate with the bores midway between their opposite ends. The outerends of the passageways 84 are respectively closed by plugs 86 I andcommunicate with upwardly extending outlet ports 83.

The outlet ports 88 are provided in a radially extending flange portion90 of the body member 52 on which there is disposed a valve ring 92. Thering 92 is provided with a plurality of valve chambers 94 respectivelycommunicating with the outlet ports 88. A flat centrally apertured valveseat member 96 is provided in each chamber 94 and a flat one way checkvalve 98 is also provided in each chamber for permitting fluid to flowfrom the outlet ports and through the valve chambers while preventingreverse flow of the fluid. Preferably springs 100 are provided forresiliently biasing the valve members 98 to closed positions. Theoutlets of the valve chambers 94 communicate with an annular manifold102 provided in a ring member 1% mounted on top of the annular member92. The annular members 104 and 92 are secured to the flange 90 by meansof a plurality of screws 106 indicated in FIG. 5. The manifold 102 hasan outlet connected with the above mentioned pipe 46 which directs thefluid discharged from the driver to the pumping assembly 50.

In order to actuate the pairs of opposing pistons 7 8 and 80 in thevarious bores 76, cam or wobble plates 108 and 110 are keyed orotherwise fixed to opposite end portions of the shaft 42 within thechambers 60 and 62 respectively. Preferably lock rings 112 and 114 areprovided between the cam plates and the adjacent bearing assemblies 72and 74. In addition, hardened wear resisting annular facing elements 116and 118 are preferably provided over the cam faces of the cam members108 and 110 respectively. Bearing slide blocks 120 are respectivelyprovided between the piston '78 and the cam element 116, and similarbearing slide blocks 122 are provided between the ends of the pistons 80and the cam element 118. It will'be noted that each of these blocks hasa spherical seat 124 for accommodating a rounded end 126 of anassociated piston. These blocks are free to slide over their associatedcam elements 116 and 118 as the cam elements are rotated by the shaft42. Of course, relative sliding action will take place between thebearing blocks and the rounded ends of their associated pistons. Thebearing blocks are maintained in assembled relationship between the camelements and the pistons merely by the clamping pressure exerted throughthe pistons, which clamping pressure is provided by springs 128 betweeneach pair of opposing pistons and by the fluid pressure created during apumping operation.

It is important to note that the cam plates 108 and 119 are formed andconnected to the shafts 42 so that their opposing annular cam facesprovided by the elements 116 and 118 are disposed in planes inclined atidentical but oppositely arranged acute angles with respect tothelongitudinal axis of the shaft 4-2. In other words, the cam platesare oppositely disposed so that they will serve to actuate each pair ofpistons 78 and in opposing relationship. For example, with the elementsin the positions shown in FIG. 3, the pistons '78 and 80 at the lefthandside of the drawing are aligned with the lowermost portions of the camsurfaces so that both of these pistons are fully retracted or, in otherwords, these pistons have completed their suction strokes and are readyto begin their pumping strokes. It will be appreciated that as the camplates are rotated, theopposing pistons will be axially shifted towardeach other in unison so as to pump fluid which has been sucked into thebores '76 outthrough the associated discharge passageways and checkvalve chambers 94. It is important to note that during such a pumpingoperation, the axial thrusts exerted on the cam plates 1G8 and will beequal and oppositely directed. As a result of the fact that both carnthrust loads are absorbed in the common shaft none of the thrust load istransferred to the housing, thus obviating the necessity for thrustbearings.

In accordance with another important feature of the present invention,the driver is provided with a novel construction for controlling thepumping operation of the various pistons. More specifically, a rotaryvalve member 130 is mounted on the shaft 42 and secured against rotationrelative to the shaft by an elongated key 132. However, the valve member130 is adapted to be shifted axially of the shaft 42 in the mannerdescribed below for adjusting the output of the driver. As shown inFIGS. 3, 6, 7 and 8, portions of the peripheral'surface of the valvemember 130 are cut away as at 134, 136, 138, and 142 so as toprovideifiuid passageway means communicating with the chambers 60 and 62within the driver and also adapted to communicate with the inlet ports82 of the various pumping chambers or bores '76. The valve member isprovided with a scroll 144 having a helical edge 146, which scroll isadapted to cover and seal the inlet ports 82 in a predetermined mannerso as to control the pumping action.

The construction and arrangement of the valve member 130 is correlatedwith the construction and arrange ment of the cam plates 108 and 110 sothat the inlet ports 82 are respectively uncovered by the scroll 144during substantially the entire suction stroke of the piston meansrespectively associated with the various inlet ports 82. It isunderstood of course that the various inlet ports will be successivelyopened as the valve member 131 rotates and the various piston means willbe succesively actuated through their suction strokes. However, theconstruction may be such that some overlapping in the suction andpumping operation of successive piston means may be obtained forpromoting the discharge of a continuous stream of fluid. It will beappreciated that since the inlet port for each pumping chamber isopenduring the entire suction stroke of its associated piston means,each pumping chamber will be completely filled with fluid or oil. Thispromotes more efiicient operation and enables the rate of discharge ofthe pumping mechanism of the driver to be accurately controlled.

It is also important to note that when a port 82 is uncovered so as toterminate pumping of fluid through an associated outlet 84, fluid willbe forced from the associated chamber back into the cavity or reservoirbetween thevalve member 130 and the member 52. The construction is suchthat when'ithis occurs, the pistonsin an adjacent chamber having anuncovered port 82 are starting their suction strokes. Thus, excess fluidspilled under pressure from one chamber serves to help fill an adjacentchamber and to prevent cavitation so as to insure complete filling ofthe chambers.

In accordance with a feature of the present invention, the pump 36 isconstructed so that a substantially shockless pumping action may beobtained. More specifically, the scroll 144 on the valve member 130 ispositioned so that when, for example, the piston elements shown at thelefthand side of FIG. 3 have completed their suction strokes and havenot yet started their compression strokes so that they are at astandstill, the scroll will accomplish complete closing and sealing ofthe inlet port 82 associated with these pistons. Thus, when thesepistons begin their pumping strokes, compression of the fluid beginsimmediately. In other Words, the pumping action starts with thepistonsat zero velocity so that any possibility of the occurrence ofsubstantial shock is eliminated. Of course the structure is such thatthe remaining pistons function in an identical manner.

Referring again to the pistons 78 and 80' at the lefthand side of FIG.3, it will be appreciated that as the cam plates continue to rotate fromthe positions shown, these pistons will be advanced toward each other soas to pump the fluid from the bore 76 and out through the associatedcheck valve chamber 94. In accordance with the present invention, thispumping action will continue until the inlet port 82is uncovered by theland or scroll 144 of the valve member 130 whereby to relieve thepressure Within the chamber 76. More specifically, the pumping actionwill continue until the valve member 138 has rotated sufficiently tocause either the helical edge 146 of the land or the narrow end 148 ofthe land to pass the inlet port 82 so as to uncover the port. It will beappreciated that the length of the pumping action may be varied eventhough the piston strokes remain constant by axially adjusting the valvemember 130 to change the time at which the helical land edge 146 passesthe port 82. In the position shown in. FIG. 3, the valve member 138 issubstantially at. its uppermost position so that the fullcircumferential extent of. the land 144 will serve to close the port 82and thereby provide for maximum pumping action and output. Upon loweringof the valve member 130 from the position shown, the helical edge of theland will be disposed so as to traverse the port 82 at any desired time,to shorten the length of the pumping action and thereby reduce theoutput of the driver. It is to be appreciated that the structure justdescribed permits substantially infinite variations in the output of thepump 36 between zero output and maximum delivery. While the operation ofthe pistons at the lefthand side of FIG. 3 and the manner in which thepumping action thereof is controlled by the valve 130 has beendescribed, it is to be understood that the remaining pistons of the pump36 are identically actuated and controlled.

In order to facilitate adjustment of the output of the pump 36, means isprovided for quickly and easily axially adjusting the valve member 130along the shaft 42. This means comprises a rod 150 which is axiallyslidably disposed within a central bore 152 formed in the lower end ofthe shaft 42. A transverse pin 154 is connected with the upper end ofthe rod 150. Opposite ends of the pin 154 extend through axiallyelongated slot means 156 formed in the shaft 42 and into complementaryapertures provided in the valve member 130 for connecting the valvemember with the rod 150. Thus by axially adjusting the rod 150, axialadjustment of the valve member 130 is accomplished. The rod 150 rotateswith the shaft 4-2 and therefore bearing means is provided at the lowerend of the rod 150 to enable the rod to be connected with means foraccomplishing adjustment thereof. This bearing means includes an innerrace 158 fixed against axial movement relative to the rod by snap rings160 and 162. An outer ball race 164 is suitably mounted within the ring166. A bar 168 is pivotally connected to the ring 166 by a pin 170. Inorder to balance the forces involved, an identical bar, not shown, maybe provided at the opposite side of the ring 166 from the bar 168 andpivotally connected thereto by a pin axially aligned with the pin 170.Additional pins 172 and 174 extend between and are secured to oppositeends of these bars. Stem means 176 which is welded or otherwise securedto the end plate 66 depends from the end plate at one side of the shaft42 and has a horizontally elongated slot 178 adjacent its lower end forreceiving the pin 1'72.

A flexible element 180 is connected with the pin 174 at the oppositeends of the bars from the pivot pin 172, which. flexible elementsextends upwardly through passageways provided in the main body member52, the cylindrical members 56 and 58 and the opposite end plates 64 and66 of the pump 36. An upper end portion of the flexible element 189 iswrapped around a small drum 182, see FIG. 4, which drum is pinned orotherwise fixed to a shaft 184; The shaft is rotatably supported by abushing 186 mounted in a suitable aperture provided in a wall of theframe means 32 of the apparatus. A hand knob 188 is fixed to an outerend portion of the shaft 184 to permit turning of the shaft and raisingor lowering of the flexible element 180. A nut member 1% is threadedonto the outer end of the shaft in such a manner that the frame wall 32and the bushing 186 are clamped between the pulley or drum 182 and theknob 188 with a force which provides sufficient frictional resistance torotation of the shaft 184- to prevent accidental or unauthorizedrotation of the shaft. It will be appreciated that upon rotation of thehand knob 188 in a direction which causes raising of the flexibleelement 180, the bar 168 will be raised so as to raise the rod 150 andthus the valve member 130. Upon opposite rotation of the hand knob 188,the bar 168 and thus the valve member 1313 are lowered. In order toinsure lowering of the valve member when the hand knob 188 is turned inthe appropriate direction, a spring 192 is compressed between the lowerend of the shaft 42 and the bearing race 158. An indicator plate 191 maybe secured to the frame for cooperating with the knob which may becalibrated for indicating to an operator the output for which the pump36 has been adjusted.

It will be appreciated that during a pumping operation the bearingpressures between the mating surfaces of the pistons and the bearingblocks 128 and 122 and between the blocks and the cam elements 116 and118 will be very high. In order to prevent undue wear of the matingbearing surfaces, the pistons and the bearing blocks are formed in amanner which insures lubrication of the surfaces after each pumpingstroke of the pistons. More specifically, the pistons 78 and arerespectively provided with relatively large passageways 194 and 196which extend axially from the counterbores which receive opposite endsof the springs 128. The passageways 194 and 196 respectively merge withrestricted orifices 198 and 200 which open centrally of the rounded endsof the pistons and communicate with enlarged passageways or chambers 202and 204 in the bearing blocks 121) and 122. These last mentionedpassageways or chambers merge with restricted orifices 206 and 208formed centrally in the bearing blocks and 122, which orifices in turncommunicate with relatively large diameter recesses or chambers 211i and212 which open at the cam engaging ends of the bearing blocks.

During a pumping stroke of the pistons, the pistons are forced againstthe bearing blocks and the bearing blocks are in turn forced against thecam elements 116 and 118 with suflicient force to prevent fluid or oilfrom leaking between the mating surfaces of these elements. At the sametime, fluid is forced under high pressure and in a slightly compressedstate through the passageways and restricted orifices in the ends of thepistons into the chambers 202418 and 284-212. As long as the pumpingpressure is maintained the fluid will remain trapped and in a compressedstate in these chambers in the bearing blocks. When the pumping pressureis relieved by the opening of the outlet port 82, the forces clampingthe pistons against the bearing blocks and the bearing blocks againstthe cam elements are also largely relieved. The fluid or oil underpressure and in a compressed state in the chambers in the bearing blockstends to flow back toward the passageways 194 and 196 in the pistons butsuch flow is retarded by the restricted orifices 198 and 268 and 286 and208. As a result of these restrictions to such reverse flow and of thefact that the pressure between. these various bearing surfaces isrelieved, the fluid and the pressure in the chambers in the bearingblocks is forced out between the mating surfaces of the pistons and thehearing blocks and between the mating surfaces of the bearing blocks andthe cam elements 116 and 118 so as to lubricate these surfaces. As willbe understood, this lubricating action takes place at the end of eachpumping stroke of the pistons so that constant lubrication of thesemating surfaces is continuously insured.

While the preferred embodiment of the present invention has been shownand described herein, it is obvious that many structural details may bechanged without departing from the spirit and scope of the appendedclaims.

The invention is claimed as follows:

1. A pump structure comprising a rotatable shaft, body means surroundingsaid shaft and providing a plurality axially spaced portions of saidshaft at opposite ends of said body means and between said first andsecond bearing means for actuating said pump elements in opposition toeach other so that thrust of said pump elements against said pair ofactuating means is absorbed in said shaft, said body means havingcombined inlet and vent apertures communicating with said chambersbetween said pump elements, means providing outlets communicating withsaid chambers betweensaid pump elements, check valve means includingannular seats and valve elements axially shiftable and engageable withsaid seats respectively connected with said outlet means for preventingreverse flow to the outlet means, a rotary valve member axially slidableon and rotatable with said shaft for cooperating with said combinedinlet and vent apertures for controlling venting of said chambers andthereby controlling the pump output, and means connected with said valvemember through said shaft for axially adjusting said valve member forvarying the pump output.

2. A pump structure as defined in claim 1, wherein said opposing pumpelements have hollow end portions, said 8 pump structure comprisingcompression springs disposed between said pump elements'and extendinginto said hollow end portions for biasing the pump elements away fromeach other.

3. A pump structure, as defined in claim 1, wherein said rotary valvemember isdisposed and actuated for closing said inlet and vent portswhen said pump elements have reached ends of their suction strokesandhave substantially zero velocity soas to obtain substantiallyshockless pumping action.

4. A pump structure,.as defined, in claim 1, wherein said pump elementshave rounded opposite outer end surfaces, said opposing means havinggenerally axially facing annular cam surfaces inclined at opposite acuteangles with respect to the longitudinal axis of said shaft, said pumpstructure including a pair of bearing blocks respectively disposedbetween the rounded end surfaces of said pump elements and the adjacentcam surfaces, said bearing blocks having bearing surfaces complementaryto said rounded surfaces and the cam surfaces, and aperture meansextending generally axially'through said pump elements and said bearingblocks for directing fluid from the pump chamber to said bearingsurfaces for lubricating purposes.

References (Iited in the file of this patent UNITED STATES PATENTS1,697,853 Coursen Ian. 8, 1929 1,934,344 Coles Nov. 7, 1933 2,142,086Alden Jan. 3, 1939 2,403,854 Geyer et al July 9, 1946 2,405,938 BeehAug. 20, 1946 2,492,688 Dall Dec. 27, 1949 2,573,792 Jakobsen Nov. 6,1951 2,709,339 Edelman et al May 31, 1955 2,745,350 Capsek May 15, 19562,842,068 Sundin July 8, 1958 FOREIGN PATENTS 980,939 France May 21,.1951

OTHER REFERENCES German Application, S31175Ia/59a, May 17, 1956. GermanApplication, K16993Ia/ 59a, Mar. 22, 1956.

1. A PUMP STRUCTURE COMPRISING A ROTATABLE SHAFT, BODY MEANS SURROUNDING SAID SHAFT AND PROVIDING A PLURALITY OF PUMP CHAMBERS SPACED AROUND SAID SHAFT, SAID SHAFT EXTENDING THROUGH SAID BODY MEANS, FIRST AND SECOND BEARING MEANS ROTATABLY SUPPORTING SAID SHAFT AT OPPOSITE ENDS OF SAID BODY MEANS, A PLURALITY OF PAIRS OF OPPOSITELY DISPOSED RECIPROCABLE PUMP ELEMENTS RESPECTIVELY WITHIN SAID CHAMBERS, A PAIR OF OPPOSING MEANS CONNECTED WITH AXIALLY SPACED PORTIONS OF SAID SHAFT AT OPPOSITE ENDS OF SAID BODY MEANS AND BETWEEN SAID FIRST AND SECOND BEARING MEANS FOR ACTUATING SAID PUMP ELEMENTS IN OPPOSITION TO EACH OTHER SO THAT THRUST OF SAID PUMP ELEMENTS AGAINST SAID PAIR OF ACTUATING MEANS IS ABSORBED IN SAID SHAFT, SAID BODY MEANS HAVING COMBINED INLET AND VENT APERTURES COMMUNICATING WITH SAID CHAMBERS BETWEEN SAID PUMP ELEMENTS, MEANS PROVIDING OUTLETS COMMUNICATING WITH SAID CHAMBERS BETWEEN SAID PUMP ELEMENTS, CHECK VALVE MEANS INCLUDING ANNULAR SEATS AND VALVE ELEMENTS AXIALLY SHIFTABLE AND ENGAGEABLE WITH SAID SEATS RESPECTIVELY CONNECTED WITH SAID OUTLET MEANS FOR PREVENTING REVERSE FLOW TO THE OUTLET MEANS, A ROTARY VALVE MEMBER AXIALLY SLIDABLE ON AND ROATABLE WITH SAID SHAFT FOR COOPERATING WITH SAID COMBINED INLET AND VENT APERTURES FOR CONTROLLING VENTING OF SAID CHAMBERS AND THEREBY CONTROLLING THE PUMP OUTPUT, AND MEANS CONNECTED WITH SAID VALVE MEMBER THOUGH SAID SHAFT FOR AXIALLY ADJUSTING SAID VALVE MEMBER FOR VARYING THE PUMP OUTPUT. 